Annual variation in Great Skua diets: The importance of commercial fisheries and predation on seabirds revealed by combining dietary analyses

S. Bearhop*, D. R. Thompson, R. A. Phillips, S. Waldron, K. C. Hamer, C. M. Gray, S. C. Votier, B. P. Ross, R. W. Furness

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)

Abstract

This study combines conventional dietary assessment with stable isotope techniques to describe Great Skua (Stercorarius skua) diet. Stable carbon and nitrogen isotope ratios in feathers of Great Skua chicks collected over three years were analyzed in conjunction with pellet and regurgitate collections. A significant drop in trophic status was detected in 1997, which likely resulted from an increase in herring and mackerel in the diet. These items were almost certainly obtained from a commercial trawler, as evidenced by a significant drop in territorial attendance during the ship's absence. Feathers yielded significantly different δ13 values among years, and part of this may have been related to a period of enhanced phytoplankton growth during 1996. A combined approach, such as the one described here, is likely to become increasingly useful in elucidating the diets of polyphagous birds.

Original languageEnglish
Pages (from-to)802-809
Number of pages8
JournalCondor
Volume103
Issue number4
DOIs
Publication statusPublished - 1 Nov 2001

Keywords

  • Dietary analyses
  • Fisheries
  • Pellets
  • Regurgitates
  • Seabirds
  • Stable isotopes

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Animal Science and Zoology

Fingerprint

Dive into the research topics of 'Annual variation in Great Skua diets: The importance of commercial fisheries and predation on seabirds revealed by combining dietary analyses'. Together they form a unique fingerprint.

Cite this